关键词: 废弃轮胎钢纤维, 矸石胶结充填体, 力学特性, 本构模型, 微观结构

Abstract: In order to solve the problems of poor toughness, brittle failure and instability of gangue cemented backfill during deep filling mining, waste tire steel fiber was used to improve the mechanical properties of gangue cemented backfill. The stress-strain curve characteristics, constitutive model and the action mechanism of waste tire steel fiber were studied by uniaxial compression test. The results show that the peak strain increases significantly, but the peak stress decreases, the post-peak curve is gentle, the residual strength is high, and the filling body changes from brittle failure to ductile failure. The modified constitutive model can reflect the stress-strain relationship and the residual strength characteristics of steel fiber backfill mixed with waste tire well. The scanning electron microscopy showed that the waste tire steel fiber was not directional embedded in the backfill matrix, and bonded with the hydration products, resulting in crack resistance effect, which increased the toughness of the backfill. The research can provide theoretical basis and engineering design reference for steel fiber modified gangue cemented backfill of waste tire.